Process of dyeing sulfur colors.



Unrrnn Snares ATlENT FFICE.

ADOLF KERTESZ, OF FRANKFORT ON-THE-MAIN, GERMANY, ASSIGNOR TO LEOPOLD CASSELLA & CO., OF FRANKFORT-ON-TIIE-MAIN, GERMANY.

PROCESS GF DYEING SULFUR COLORS.

SPECEFIGACJIUN forming part of Letters Patent No. 693,653, dated February 18, 1902 Application filed May 4, 1901. Serial No. 58,805. (No specimens.)

T0 aZZ whom, it may concern:

Be it known that I, ADOLF Knn'rnsz, a citizen of Prussia, and a resident of Frankforton-the-Main, in the Province of Hesse-Nassau and Kingdom of Prussia, Germany, have invented certain new and useful Improvements in Processes of Dyeing Sulfid Colors, of which the following is a specification.

At all times cases have been observed where cotton which had been subjected to different processes of dyeing suffered in its tensile strength. Sometimes this could be observed at once, sometimes only after prolonged storing. This was experienced with anilin-black and other dyestuffs, and particularly after the introduction of the direct-dyeing sulfid colors into the cotton-dyeing industry a diminution of the tensile strength of the fiber could be noticed in single cases. Some dyestufis of this group showed the said defect in a higher and some in a less degree and even the best members of the group, such as immedial black, were not entirely exempt. It was soon discovered that in the case of using the sulfid colors the after treatment was often the cause of the tendering of the fiber. Copper salts alone, chromates, and sulfuric acid have a detrimental influence. This cause of the destruction of the fiber was in most cases overcome by substituting more suitable methods of after treatment, (chromic salts.) I have now arrived at the following unexpected results: If the final operation of the dyeing process consisted in a treatment with acid, even if afterward the dyed goods were rinsed in pure water, the danger of a tendering of the cotton fiber was found to exist-for instance, when, as usual, the cotton was brightened with acids (acetic acid) or when it formed part of union goods and these were subsequently dyed in acid-baths. Nowif certain salts are added to the last rinsing-bath or are by some other means incorporated into the cotton fiber all respective tests have uniformly demonstrated that neither prolonged storage nor steaming or potting and sponging effected a noticeable change in the structure and tensile strength of the cotton. Such salts are, in the first place, the acetates. Acetate of soda, acetate of potash, acetate of ammonia, acetate of magnesia, &c., act in almost the same man- 'the fast-dyed cotton is interwoven with White ner; but also a number of other salts-such as the formiates, borates, and tungstateshave proved suitable, although not in all cases quit-e equaling the acetates in their efficiency. As a general rule it has been determined that those salts yield the desired effect which,

without being alkaline themselves, are capable of neutralizing free mineral acids, either by transposition or by forming acid salts.

Them ethod of application on cotton-hanks is illustrated by the following example: Fifty kilos of cotton yarn are dyed for one hour at the boil in a starting-bath charged with five kilos soda, five kilos sodium sulfid, forty kilos common salt, and nine to ten kilos immedial black, then rinsed and after treated for onehalf hour at the boil in a second bath containing one and one-half per cent. bichromate of potash, one and one-half per cent. chrome alum,and three per cent. acetic acid. The yarn is then rinsed and treated at once or after a passage through a soap-bath in a bath (acidulated with acetic acid) containing ten grams acetic acid and five to ten grams acetate of soda per liter of Water. The yarn is worked for some minutes in this bath, then hydroextracted without being rinsed, and dried.

Usually when manufacturing union goods wool and the piece then dyed with wool colors in an acid-bath, (cross-dyeing.) The application of the new method is for this purpose illustrated by the following example: One hundred kilos of a fabric consisting of a cotton warp dyed with ten per cent. immedial black, after treated with bichromate of potash and chrome alum and of a. white Wool weft, are dyed with six per cent. naphthylamin black S (of the weight of the wool) with the addition of bisulfate of soda. The goods are then rinsed in water and passed through a bath containing five grams acetate of soda per liter of water. Subsequently they are dried at once and finished as usual. 5

In the velvet industry it is customary that the ready-dyed black goods receive a coating of Prussian blue mixed with linseed-oil for brightening purposes and are then air dried." The weak acid resulting from the oxidation of the linseed-oil is in this case already sometimes dangerous. The following example illustrates the application of the new method of preserving the tensile strength in this instance: Fifty kilos of velvet are dyed in the vat with twelve per cent. immedial black FF, six per cent. sodium sulfid, and ten per cent. common salt, then rinsed, and after treated with one and one-half per cent. of bichromate of potash, one and one-half per cent. chrome alum, and three per cent. acetic acid. After being rinsed again the pieces are passed through abath charged with five'to ten grams acetate of soda per liter of liquor and thereafterdriedwithoutanyfurther rinsing. After having been dried the socalled blue mass, consisting of a mixture of Prussian blue with linseed-oil, is applied to the pieces, which are then hung upfor several days in a Warm place.

In these applications of the new method it is of course immaterial in which manner the acetate or the respective salts which have an analogous effect are incorporated into the fiber. Instead of using baths the goods may finally be padded, for instance, with such solutions, or the latter be brushed on.

The method has hitherto yielded excellent results, particularly when the following dyestuffs were used: immedial black, immedial blue, (and of course also the corresponding products brought on the market under other denominations,) immedial brown, katigene black, katigene green, katigene olive, katigene brown, cross-dye black, Vidal black, sulfid black, kryogene blue, anthraquinone black, and St. Denis black.

Having now described my invention and in what manner the same is to be performed, what I claim is The process of treating cotton fiber dyed with sulfur colors and subjected afterward to the action of acids with solutions of acetates substantially as described.

Signed at Frankfort-on-the-Main, in the Province of Hesse-Nassau and Kingdom of Prussia, this 29th day of March, A. D. 1901.

AD OLE KER'IESZ.

Witnesses:

JEAN GRUNDL 7 CARL GRUND. 

